The invention concerns an oscillating piston compressor. Certain oscillating piston compressors have become known as "Dry-Running Compressors" comprising an impeller-like piston axially resting on a piston rod for oscillating back and forth thereon in a cylindrical piston housing. With this known oscillating piston compressor, the piston housing contains at least one radial intermediate wall in order to create a limit for a compression chamber. An isolating or sealing strip arrangement is not effectively feasible with this design, so that compressed air may escape from the compression chamber into the suction or intake chamber. This situation results in a poor degree of compressing efficiency and in uncontrolled temperature variations, especially increase.
Another design of an oscillating piston compressor, more favorable with regard to the packing strip arrangement, is characterized by a spherical housing divided at the area of its largest diameter for the purpose of mounting the rotating piston. Due to such division of the housing, a cumbersome, two-part piston must be used. A unitary piston cannot be used in this last-mentioned type compressor, since it would have to travel over a junction seam. This could lead to rapid wear and possibly even to rupture of the sealing element.
With the last-mentioned oscillating piston compressor, oscillation of the pistons is effected by a hobbing or camming action taking place over steep cam surfaces. This results in a one-sided compression chamber, which leads to unequal thermal stresses of the housing.
In the case of the presently known oscillating piston compressors above described, the operation is complicated because of the housing design. An arrangement of the drive within the housing is not directly possible, so that an economic production and use is not possible without additional expenditure. For this reason, a further known oscillating piston compressor has been proposed in which the radial intermediate walls are eliminated, so that a piston having semi-circular sectors may be used advantageously with a spherically-shaped housing having a correspondingly spherically-shaped interior chamber, and in which housing the drive arrangement may be accommodated.
To attain the aforementioned advantage, the further known oscillating piston compressor is characterized by the following features:
(a) a blade-like disk, oscillating back and forth in the housing inner chamber on a bearing axle, whose oscillating movement is effected by means of a drive, forms the oscillating piston; PA1 (b) the blades of the oscillating piston making sealing contact with the inner spherical surface of the housing, form two compression chambers in cooperation with the internal surface of the housing inner chamber and the valve plate; PA1 (c) charging of the compression chambers takes place from the atmosphere by means of inlet valves or scavenging ports; PA1 (d) delivery of compressed air from compression chambers to the devices using the compressed air takes place via pressure valves; PA1 (e) the cylinder bearing surface is designed spherically and does not have juncture seams in the area of contact by oscillating movement of the piston which is complementarily designed to correspond to the spherical radius of the housing; PA1 (f) the bearing axle of the oscillating piston represents the geometric center point of the sphere diameter; PA1 (g) the compression chambers, limited by the intermediate wall, designed as a valve plate, and by the surfaces of the piston, are each semi-circularly wedge-shaped.
With the oscillating piston compressor immediately above described, the wedge shape of the compression chambers necessarily results from the wedge-shaped or angled cover-valve plate, while the piston represents a uniform disk having a circular peripheral support surface. The spherical recess in the cylinder housing required by the wedge shape of the cover-valve plate provides an elliptical sealing surface, due to which, difficulties can originate with the manufacture thereof and which can also affect the manufacture of the cover-valve plate and the cylinder cover.